The effect mechanism of static electric field on the propagation of surface acoustic wave(SAW) in piezoelectric film is discussed. Firstly, the initial stress and the initial displacement of piezoelectric film in static electric field are deduced. Secondly, the phase velocity change and the dispersion curve of SAW are obtained by solving the coupling wave equation of piezoelectric medium. Finally, the propagation characteristics of SAW in ZnO and AlN piezoelectric films are simulated and analyzed. The results show that the phase velocity of SAW is proportional to the magnitude of static electric field and inversely proportional to the magnitude of wave number.